A 2:1 receptor/C60 complex as a nanosized universal joint

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Materials Science

Background:

• Corannulene derivatives are known molecular receptors for fullerenes.
• Previous buckycatcher designs showed moderate C60 affinity.
• Developing selective and high-affinity fullerene receptors remains a challenge.

Purpose of the Study:

• To synthesize and characterize Buckycatcher II, a novel corannulene-based receptor.
• To investigate the binding affinity and complex formation of Buckycatcher II with C60.
• To elucidate the structural features of C60-Buckycatcher II complexes in solution and solid states.

Main Methods:

• Synthesis of Buckycatcher II (C51 H24).
• Spectroscopic and analytical techniques to study C60 binding.
• X-ray crystallography to determine the solid-state structure of complexes.

Main Results:

• Buckycatcher II exhibits significantly higher affinity for C60 compared to previous receptors.
• Formation of a 1:1 C60 @catcher inclusion complex.
• Detection of a trimeric C60 @(catcher)2 assembly in solution and solid states.
• X-ray analysis revealed a unique "universal joint" crystal packing in the trimer.

Conclusions:

• Buckycatcher II represents a significant advancement in molecular receptors for fullerenes.
• The receptor's design enhances C60 binding affinity and enables the formation of novel supramolecular architectures.
• The findings provide insights into host-guest complexation and crystal engineering with fullerenes.